ViewConfig: Add 'Dynamic Wrap At Static Marker' option

Summary:
Without this patch is in "Dynamic Wrap Mode" the text always wrapped
at the outer end of the view, which may hinder the reading flow with
a wide screen.

Test Plan:
Normal behaviour

With patch and activated option

Config page, no old one (sorry, but looks almost the same just without the new option)

Reviewers: KTextEditor, VDG, cullmann

Reviewed By: KTextEditor, cullmann

Subscribers: cullmann, kwrite-devel, kde-frameworks-devel, KTextEditor

Tags: Kate, Frameworks

Differential Revision: https://phabricator.kde.org/D17661